CAUSES, SYMPTOMS, PREVENTION, AND TREATMENT OF VARIOUS ANIMAL DISEASES

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1 ANIMAL SCIENCE 8822-B INTRODUCTION CAUSES, SYMPTOMS, PREVENTION, AND TREATMENT OF VARIOUS ANIMAL DISEASES It is impossible to accurately estimate all the losses caused by livestock diseases, but the United States Department of Agriculture estimates that losses caused by mortality, reduced productivity, lower fertility, condemned products, and restricted access to potential markets exceed 17.5 billion dollars annually in the United States. Those losses represent almost 17% of the production costs associated with the livestock industry. Livestock production is an integral part of the way-of-life for the people of the world. Many farmers and ranchers depend upon livestock production for their livelihoods. Consumers expect adequate supplies of meat at economical prices. With livestock mismanagement and spread of diseases*, we are all affected. CAUSES OF DISEASES Disease causes body functions to disfunction or function improperly. Three principal reasons most often cited for the spread of diseases are poor sanitation, improper management, and introduction of new animals into a herd. One or more of the following defects cause diseases. Nutritional defects - An imbalance of required food nutrients in the ration is the cause of nutritional defects. Animals receiving inadequate amounts of vitamins, minerals, fats, carbohydrates, and protein cannot produce efficiently. Therefore, their levels of resistance to disease are lowered. Physiological defects - These defects cause an improper functioning of glands, organs, or body systems. The relationship between the diet and the proper functioning of body parts is directly related. For example, the thyroid gland regulates the rate of body metabolism and depends upon an adequate supply of iodine to function properly. An improperly functioning thyroid gland may increase the nutritive requirements of animals to the point that very few nutrients are available for growth or production. * Underlined words are defined in the Glossary of Terms

2 Morphological defects (physical defects) - An accident or negligence is responsible for physical defects. Cuts, scrapes, scratches, bruises, and broken bones are examples of morphological defects. Any one of these can temporarily or permanently reduce the efficiency of an animal. Good management practices help eliminate defects of this nature. Pathogenic defects - Certain organisms produce toxins or poisons that upset the normal metabolic activity of the animal. Viruses and bacteria are the most common disease-causing pathogens. They are microscopic in size and capable of multiplying rapidly under ideal environmental conditions. Other pathogens are fungi and protozoans. A discussion of each type follows. Viral diseases are the most difficult to control because viruses closely resemble the chemical compounds that make up a cell. Another problem in controlling viruses is that the chemicals capable of killing or controlling them also kill or destroy the host cell. Preventive vaccinations are the most successful method of controlling viral diseases. Bacteria are microscopic in size, produce powerful toxins, and multiply rapidly. Many bacteria are capable of forming spores, resistant forms of bacterial cells able to withstand severe environmental conditions. These spores are difficult to control and may lie dormant for years before being provided with the opportunity to cause disease. Antibiotics are used successfully to control bacteria. Fungal diseases are caused by fungi, which are small organisms. Many disease-producing fungi live in the soil. It is often difficult to determine the cause of fungal diseases, because bacteria cause a secondary infection and are often erroneously identified as fungi. Protozoa are one celled and the simplest form of animal life. Some protozoa cannot move themselves and must be transported by other means. Some move by making whip-like lashes or vibrating projections. A number of different kinds of protozoa prey upon animals and cause disease. EIGHT GOOD MANAGEMENT PRACTICES Animals to be added to a herd should be isolated 3 to 4 weeks before they are placed with the herd. This includes both new animals and those removed from the herd and exposed to other animals. A sound immunization program should be followed. Clean, healthful surroundings should be provided. Rations must be nutritionally adequate. Visitors and new animals should not be allowed in the livestock area. Diseases should be accurately and quickly diagnosed. A competent veterinarian should be consulted when a health problem arises. Livestock should be handled properly. Examples of how to handle animals include the following: o Canvas slappers, rather than clubs and whips, should be used. o Protruding nails and broken boards should be eliminated. o Machinery and equipment should be removed from the lot. o Horned cattle should be dehorned. o Barns and trucks should be bedded properly. o Animals should be loaded slowly and carefully. o Partitions should be used to separate different classes of livestock. o Livestock should be protected from inclement weather

3 CHARACTERISTICS OF COMMON DISEASES Disease Cause Symptoms Prevention & Control NUTRITIONAL DEFECTS Anemia Bloat All farm animals are susceptible. Iron deficiency prevents the formation of hemoglobin, a red ironcontaining pigment in the red blood cells responsible for carrying oxygen to the cells. Typically occurs when animals are grazing on highly productive pastures during the wetter part of late spring Characterized by general weakness and a lack of vigor. Swollen abdomen on the left side, labored breathing, profuse salivation, groaning, lack of appetite, & stiffness. & summer. Colic Improper feeding. Pain, sweating, & constipation, kicking, & groaning. Enterotoxemia Bacteria & overeating. Constipation is an early symptom & sometimes followed by diarrhea. Founder VIRAL DISEASES Overeating of grain, or lush, highly improved pasture grasses. Affected animals experience pain and may have fever as high as 106 degrees F. Cholera Caused by a filterable virus. Loss of appetite, high fever, reddish-purplish patchwork of coloration on the affected stomach, breathing difficulty& a wobbly gait. Equine Encephalomyelitis Hemorrhagic Septicemia Newcastle Viruses classified as group A & B are transmitted by bloodsucking insects, such as the mosquito. Caused by a bacterium that seems to multiply rapidly when animals are subject to stress conditions. Poultry disease - caused by a virus that is spread by contaminated equipment or mechanical means. Fever, impaired vision, irregular gait, muscle spasms, a pendulous lower lip, walking aimlessly. Fever, difficultly breathing, a cough, & discharge from the eyes & nose. Chicks make circular movements, walk backwards, fall, twist their necks so that their heads are lying on their backs, cough, sneeze, and develop high fever & diarrhea. Warts A virus causes warts. Protruding growths on the skin. A balanced ration usually prevents the occurrence of anemia. Maintain pastures composed of 50% or more grass. Careful feeding. Bacterin or antitoxin vaccine should be used at the beginning of the feeding period. Good management & feeding practices prevent the disease. A preventive vaccine is available. No effective treatment. Producers should use good management. Control of carrier, use of a vaccine. Vaccination several days prior to shipping or other periods of stress. Several types of Newcastle vaccines are available, antibiotics are used in treating early stages of the disease. No known preventive measures. Most effective means is with a vaccine

4 BACTERIAL DISEASES Pneumonia Tetanus Atrophic Rhinitis Anthrax Blackleg Brucellosis Distemper Erysipelas Leptospirosis Tuberculosis CHARACTERISTICS OF COMMON DISEASES (continued) Bacteria, fungi, dust, or other foreign matter. The bacterium, pasturella multiocida, is often responsible for the disease. A spore-forming anaerobe bacterium is the cause. The spores may be found in the soil & feces of animals. Two different bacterium, Bordetella bronchiospetica & Pasturella, cause atrophic rhinitis. A spore-forming bacterium causes the disease. (Cattle-Sheep) A spore-forming bacterium that remains in an area permanently. The germ has an incubation period of one to five days & is taken into the body from contaminated soil & water. Caused by bacteria. Brucella abortus is the bacterium. (Horses) Contagious. Exposure to cold, wet weather, fatigue, and an infection of the respiratory tract aid in spreading the disease. A resistant bacterium capable of living several months in barnyard litter. Caused by a bacterium found in the blood, urine & milk of infected animals. Three types of tubercle bacilli causing the disease are human, bovine, & avian. The human type rarely produces TB in lower animals, but the bovine type is capable of producing the disease in most warm-blooded vertebrates. The avian type produces the disease in birds & swine. A general dullness, failing appetite, fever & difficulty breathing. Difficulty swallowing, stiff muscles, & muscle spasms. Affects the nose, making it crooked and wrinkled. Sneezing, nose bleeds, and a tear-stained face occur. Fever, swelling in the lower body region, a bloody discharge, staggering, trembling, difficult breathing, & convulsive movements. Lameness, followed by depression & fever.. The muscles in the hip, shoulder, chest, back, & neck swell. The abortion of the immature fetus is the only sign in some animals. Increased respiratory rate, depression, loss of appetite & discharge of pus from the nose are visible symptoms. Infected animals have fever & swollen lymph glands, located under the jaw Three forms: acute, subacute, & diamond skin form. Acute: constipation, diarrhea, & reddish patches on the skin. Subacute: usually localized in an organ such as heart, bladder, or joints. Sloughing off of the skin is common. Causes abortion & sterility. Symptoms are blood-tinged milk & urine. Lungs are affected. However, other organs may be affected. Some animals show no symptoms; others appear unthrifty & have a cough. Proper housing, ventilation, sanitation, and antibiotics. Immunizing animals with a tetanus toxoid. Sanitation and a good health program are important for prevention. Vaccines are available. An annual vaccination. Manure & contaminated materials should be burned & area disinfected. Insects should be controlled. A preventative vaccine. Vaccinating calves with Br. abortus prevent cattle from contacting the disease. Infected cattle must be slaughtered. Animals with disease should be isolated, provided with rest, protected from the weather, and treated with antibiotics. An anti-swine erysipelas serum is available. Susceptible animals should be vaccinated. Maintaining a sanitary environment & comfortable quarters help prevent the disease

5 Pullorum CHARACTERISTICS OF COMMON DISEASES (continued) Poultry disease caused by a bacterium that is capable of living for months in a dormant state in damp, sheltered places. The germs infect the ovary & are transmitted to the chicks through the eggs. Infected chicks huddle together with their eyes closed, wings drooped, feathers ruffled, & have foamy droppings. Blood test is required for positive identification of the disease. Disposal of infected hens aids in preventing the disease. Chicks should be purchased from a certified pullorum-free hatchery. FUNGAL DISEASES Foot Rot Calf Diphtheria A fungus common to filth is responsible for foot rot. Animals are most apt to contact foot rot when forced to live in wet, muddy, unsanitary lots for long periods of time. Lives in soil, litter, & unclean stables& enters the body through small scratches or wounds. Skin near the hoof-line is red, swollen, & often has small lesions. Difficulty breathing, eating, and drinking. Patches of yellowish, dead tissue appear on the edges of the tongue, gums, & throat. Often, a nasal discharge occurs. Maintaining clean, welldrained lots is an easy method of preventing foot rot. The diseased tissue is removed to expose healthy tissue, which is treated by swabbing it with tincture of iodine. PROTOZOAN DISEASE Coccidiosis A protozoan of which several species is responsible. Occurs in two forms: cecae and intestinal. Cecae is the acute form that develops rapidly & causes high mortality rate, bloody droppings, & sudden death. Intestinal coccidiosis is chronic in nature, and its symptoms are loss of appetite, weakness, pale comb, & low production. Few deaths occur from the latter form. Because the disease is transmitted in feces, maintaining sanitary conditions & feeding a coccidiostat prevent the disease. DISEASE PREVENTION Prevention is the key to controlling animal diseases. Sanitation is the key to prevention of diseases. Most disease-causing agents enter the body through some type of body opening, such as the nose, eyes, mouth, or wound incision. Pathogens may be spread by direct contact, or indirectly by the wind, water, feed, or other animals. After entering the host, a pathogen must overcome the natural resistance of the body to produce the disease. The following management practices are possibly the best methods of controlling diseases. Provide an environment that prevents or restricts the growth of pathogens (sanitation). Provide a balanced diet. Provide protection from accidental injury

6 The practices include the following standards for the animals living quarters. Sufficient space for all animals. Crowded conditions tend to promote the incidence of disease. Fresh air and temperature control through ventilation. Good drainage. Floors and pens must be kept dry and clean. Bedding must be kept fresh, and manure should be disposed of often. Systematic pasture rotation system. This is a practical method of disease and parasite control. It breaks the life cycle of pathogens by removing the host. The ultraviolet rays of sunlight kill pathogens when the pasture does not have livestock in it to reinfest it. Use of disinfectants. Chemicals that restrict the growth of pathogens should be used regularly. Soap and boiling water are two inexpensive disinfectants available to livestock producers. GOVERNMENT REGULATIONS Governmental regulations controlling the transportation and sale of diseased animals are strict and complex. It is important that the livestock producer recognize available assistance through the local veterinarian. The services of the local veterinarian should be used in establishing a disease prevention program and as a source of information on governmental regulations affecting the producer. SUMMARY Proper management practices are the keys to profitable livestock enterprises. Many variables cause diseases, but consulting local veterinarians and learning about the diseases reduce the incidence of the diseases. If mismanagement and livestock diseases are allowed to spread, everyone loses. SELECTED WEB SITES FOR INFORMATION RELATED TO ANIMAL DISEASES Acknowledgements Kristy Corley, Graduate Technician, Department of Agricultural Education, Texas A&M University, revised this topic. Larry Ermis, Curriculum Specialist, Instructional Materials Service, Texas A&M University, reviewed this topic. Vickie Marriott, Office Software Associate, Instructional Materials Service, Texas A&M University, prepared the layout and design for this topic. Christine Stetter, Artist, Instructional Materials Service, Texas A&M University, prepared the illustrations for this topic. REFERENCES Agricultural Research Service U.S.D.A. Animal Health. [Online]. Available: [2002, July]. Baker, James K. and William Greer. Animal Health - A Layperson s Guide to Disease Control. Prentice- Hall, Incorporated: Upper Saddle River, NJ. March

7 GLOSSARY OF TERMS Antibiotic A chemical substance produced from microorganisms and used to kill other microorganisms. Diseases Impairments that affect the performance of vital life functions. Metabolism The phenomena of chemically changing feedstuffs into complex tissue elements and complex substances into simple compounds. Morphological defects Physical defects caused by accident or negligence. Nutritional defects Defects caused by an imbalance of nutrients in a ration. Pathogenic defects Defects caused by pathogenic organisms such as bacteria and viruses. Physiological defects Defects caused by improper functioning of body parts such as glands and organs. Slapper An item used while working cattle or other livestock to ensure that no damage occurs to the animal s hide. Viruses Ultra-microscopic particles reproduced in a cell that causes a reaction in the cell. SELECTED STUDENT ACTIVITIES SHORT ANSWER/LISTING: Answer the following questions or statements in the space provided or on additional paper. 1. List three principal reasons most often cited for the spread of livestock diseases. 2. List eight good management practices that should be followed by livestock producers. d. e. f. g. h. 3. List four types of pathogenic organisms. d. 4. What are the four defects that cause diseases? d. 5. Provide an example of a protozoan disease

8 6. How do most disease-causing organisms enter the body? 7. List five examples of how to properly handle animals. d. e. 8. Annual losses from livestock diseases in the United States exceed $. 9. A(n) or is the cause of morphological (physical) defects. 10. Nutritional defects can be prevented by observing good management practices and by feeding a. 11. To produce efficiently, animals must receive adequate amounts of,,,, and. 12. Living organisms capable of producing diseases are called. 13. Physiological defects cause an improper functioning of,, or. 14. Hemorrhagic septicemia can be prevented by animals several days prior to shipment or other periods of stress. 15. Equine encephalomyelitis is transmitted by insects. 16. Blackleg is taken into the body from contaminated and. 17. Protozoa are one-celled and the simplest form of. 18. is the key to controlling animal diseases. 19. After entering the host, a pathogen must overcome the of the body to produce the disease. ADVANCED ACTIVITIES 1. Select an animal disease of your choice. Research and write a report on that disease and present your findings orally to the class. 2. Research available resources on all diseases affecting a specific livestock species in your area. Then, develop a complete prevention plan and provide details of how to give and when to give vaccines and antibiotics. List other methods of preventing and controlling the diseases. ALL RIGHTS RESERVED Reproduction prohibited without written permission. Instructional Materials Service Texas A&M University 2588 TAMUS College Station, Texas